Piston



Nov. 23, 1-937. w. scHoENGARTH 2,100,203

PISTON Filed Aug. l0, 1935 fnl/enfans APotezl'iterl Nov. 23, i937 l uNi'rED S'li'lkf-S PATENT .0F-FICE amaca lll.

'My invention relates topistons, and more particularly to pistons for, internal combustion engines, and. has for its object the provision of an improved piston of this character inwhich means ,r arepmvided whereby heat controlled means may circumferentially adjust the said piston so as to maintain perfect contact irrespective of temperature.

Y My invention also has other objects which will 10 be apparent from the s'pecic description thereof.

-My invention is in many respects an improvev ment over prior Patent No. 1,688,792, issued O ctobe`r23, l1928.

v-I will describe my invention more in detailby I `15 'referring'to one form which'it may take which f, 'isxlustrated in the accompanying drawing in '-w h,-

`Iiig. 1 is a longitudinal section o f a piston constructed in accordance with my invention:

, Fig. 2 is a sectional view on line 2 2 of Fig. 1; Fig. 3 is a longitudinal sectional view at right angles to that oi' Fig. 1; and

Fig. 4 is a perspective view oi thegcontrol elei and a skirt portion Il, the head andskirt por# tions being united together by pillars I2, which .pillars have bosses Il to accommodate the crank, pin bearings. The skirt portion H is throughout its length provided with a slot I4 so that the skirt lportion may be expanded and contracted as Y will presently appear. The head portion i0 is not split and thus retains itsv circumferential outline except as it may expand or contract due to Vchanges inthe temperature thereof.

" .In order tovbring about expansion or contraction of the skirt portion, I provideva control element IS shownmore clearly in Pig. 4. This con- .'o curvature corresponding to that 'ofthe piston walls.` and this segmental portion ts between abutments Il-Il provided upon the inner walls of theskirt portion of the piston. The segmental -poi'tlon` Il is flaring so that as it is moved longitudinallyit expands the skirt portion or contracts it, asv the case may be.- the said abutments il slopinl in accordance with the daring 'nature of the segmental portion i8. 'I'he control element il has an attachment linger is whereby it t 'application sqg'ast 1c, 19st, No. 35.1343

trol element has a segmental portion i8 having a l 20 forming part of the head portion I0.V VNuts 2i serve to adjust the control element in the vposi-- tion desired when thel parts are at a given tem'- perature. j

In order to provide'for the autcmatinadjust-m ment of the circumference of theA skirt portion in accordance with the changesof the temperature of the parts, I make the parts I9, I5, and 2| of a material having a low rate of expansion due to heat.V The. parts of the piston consisting of the .10 head portion I0, the skirt portion Il, and the pil-,- A.lars l2 have a higher rate of expansion.' Thus `upon an increase in temperature as the engine is warming up, the skirt portion il .would expand outwardly as well as downwardly (Figui), but suchexpansion downwardly would cause vthe abutments i1 to slide down from the control element I thus causing the outer diameter of the said skirt portion to actually decrease at the same rate it would expand from the heat if said control element was omitted. In this manner, the .material of the proper 'coeilicients of expansion have been chosen, and the'angles of the sides of the control element l5 and of the abutments l-I also having been chosen thus the expansion of the piston may be fully compensated for throughout a wide range of temperatures s o that the piston will always closely hug the inner wall Aci? the cylider, leaving merely suiiicient space for the reiilxn oi' oil for lubrication' and sealing The nature and purpose of this invention will, it is thought,` be clear from what has thus been described, and it willl also be clear that many vmodifications may be made without departing ,'35 from the spirit of my invention.

Having, however. thus described one form which it may take, what I claim as. new and desire to secure by 'Letters Patent is:

1. A piston oi' the character described including ahead portion and a circumferentially expandible and contractible skirt portion, `slidable means i'or expanding or contracting said skirt portion and a connection between said slidable me and said head portion having a different j. coe cient of .expansion than the material composing said head and skirt portions.

2. A piston of the character described including a head portion and a circumferentialiy expandible and contractible skirt portion, connecting means between said head portion and said skirt portion, means for expanding or contracting said skirt portion connected with said head and skirt portions including means having a different coem'cient ci expansion than the material comf posing said head and skirt. portions, and bearing means adapted for association with a crank pin Y-resihently arranged in said connecting means a head portion andicircumertialiy expand- /'/i'niearforctible skirt portion, connecting 10 means between said head portion and said skirt portion, slidable means for expanding or contracting said skirt portion connected with said head and skirt portions including means having a different coeiiicient of expansion than the material composing Asaid head and skirt portions; and bearing' means adapted for association with a crank pin resiliently arranged in said connecting means whereby the expansion and contraction of said skirt portion does not disalign said bearing 20 means.

4. A piston ilthegharacter described includ- \i'ng a head portion almireuxqerentially expandible and contractible skirt portion, connecting means between said head portion and aifr expanding or contracting said skirt portion connected with said head and skirt portions including means having a different coemcient of expansion than the material composing said head and skirt portions, and bearing means adapted for 5 association with a crank pin resiliently arranged in said connecting means whereby the expansion and contraction of said skirt portion does not disalign said bearing means.

5. A piston of the character described including a head portion and a separate expandible and lcontractible skirt portion, means inside said skirt portion connecting the skirt portion with the head portion. said skirt portion being slotted lengthwise whereby it may be expanded or contracted, guide bearings on said skirt portion, a wedge member movable in said guide bearings to control the degree of opening of said slot, and positioning means for said wedge member comprising a heat responsive element securing said wedge member to said head portion, and having a slower rate of expansion than the means connecting the head portion and skirt portion.

WALTER LNARD SCHOENGARTH. 25 

